Chapter 1: Getting Started

Where you will learn how to set up a development environment for Lux.

Before any coding can happen, it is necessary to set-up everything you need to become a productive Lux programmer.

Question #1: How do I write Lux code?

Text editor support is a fundamental thing for any language, and Lux already covers some of that. The catch is that there's only support for Emacs at the moment.

The plugin is called lux-mode, and you can obtain it from this website: https://github.com/LuxLang/lux/tree/master/lux-mode.

The instructions for how to install it are at the link and it won't take much time.

Question #2: How do I build Lux programs?

Currently, Lux doesn't have a build tool of its own.

Instead, we're going to piggy-back on Leiningen, a build tool originally meant for Clojure, but that can be customized for our purposes.

Note #1: For the moment, you'll have to use Leiningen 2.7.1 instead of later versions, due to backwards incompatible changes in the latest Leiningen releases.

Note #2: Lux has not yet been updated to work with the latest versions of Java, so you'll need to have Java 8 installed on your machine to use it.

Question #3: How do I use Leiningen for Lux?

To find out, let's create a sample project that will have everything we need.

These are the steps:

1. Create a directory called my_project.
2. Create a new project file at my_project/project.clj.

3. Add this to the project file:

   (defproject my_project "0.1.0-SNAPSHOT"
     :plugins [[com.github.luxlang/lein-luxc "0.5.0"]]
     :dependencies []
     :lux {:program "main"}
     :source-paths ["source"]
    )
   

   This will fetch the Lux plugin for Leiningen, alongside the Lux standard library.

   It also tells the plugin that we'll be using the my_project/source directory for our source code, instead of Leiningen's default src directory.

   The file containing our program will be my_project/source/main.lux.

4. Create source/main.lux and add this code to it:

   (;module: {#;doc "This will be our program's main module."}
     lux
     (lux (codata io)
          [cli #+ program:]))
   
   (program: args
     (io (log! "Hello, world!")))
   

   As you can see, this is nothing more than a very simple "Hello, world!" program to test things out.

   Everything will be explained later in the rest of the book.

5. In your terminal, go to my_project, and execute lein lux build.
   When it's done, you should see a message like this:

   ...
   Compilation complete!
   "Elapsed time: 13022.487488 msecs"
   [COMPILATION END]
   

   A directory named target will have been created, containing everything that was compiled, alongside an executable JAR file.

6. Run the program with this: java -jar target/jvm/program.jar

7. Smile :)

Question #4: Where can I find documentation for Lux?

A specially useful source of information is the documentation for the standard library.

You can also explore the Lux repository on GitHub for more information.

Question #5: Bro, do you even REPL?

REPL support for Lux is still work in progress, but you can play around with it.

There is the lein lux repl command, but for reasons I can't explain right now, that won't actually run the REPL, but instead it will spit out a command that will run it for you.

If you just want to run the REPL, you can get the job done with this command:

eval "$(lein lux repl)"

You can play with it for a while and type exit when you're done.

Question #6: Where do I talk about Lux?

The place to talk about Lux is at the Lux forum.

We can proceed to the actual teaching of the language!

See you in the next chapter!